The present invention relates generally to sprayer booms, and more specifically, to suspension systems for such booms.
As a typical agricultural sprayer passes over a field during a spraying operation, the boom is constantly moving because of motions induced by the spray vehicle as it moves over irregular and sloping ground. These motions cause the boom to yaw, pitch and roll. Such movements are greatly magnified at the ends of long booms and result in spray rate and coverage fluctuations and excessive forces on the sprayer. When the boom yaws (that is, rotates about a vertical axis), one end of the boom accelerates while the other decelerates which, in some cases, causes the spray rate to double on one end of the boom and to be cut in half on the other end of the boom. When the boom rolls (that is, rotates about an axis parallel to the direction of travel), some strips of the field will get a lower spray rate while others get a higher rate. As a result, there tends to be under application or no application of chemicals in some areas and over application in other areas. Inadequate pest and weed control, wasted chemicals and reduced yields can result from improper coverage.
Some sprayers include booms suspended from a single link or pendulum to provide roll isolation. Although such a suspension reduces the variation in chemical coverage which would otherwise result from the boom roll, the variations due to yaw are still present. In addition, presently available suspended booms usually require a latch mechanism to provide hillside compensation. The operator must physically engage the latch mechanism when operating on a hillside.